ESXi host reports "Power sensor health state degraded" on HPE ProLiant Hardware

Products

• VMware vSphere ESXi

Issue/Introduction

•  vCenter Server triggers a Critical Alarm: "Power sensor health state degraded" for an ESXi host.
• Hardware health monitoring in vSphere Client shows "Power Red" or specific sensor alerts.
• Hostd logs contain entries similar to:
  Sensor nn type power, Description Power Supply 2 Power Supply 2 state assert
Sensor nn type power, Description Power Supply 1 Power Supply 1 state assert

Environment

HPE ProLiant Servers

Cause

The alarm is triggered by hardware-level events detected by the server's Baseboard Management Controller (BMC/iLO) and read via the CIM/IPMI interface. ESXi forwards these alerts from the hardware monitoring interface to vCenter.

Triggers include:

• Physical power supply failure or voltage irregularity.
• Disconnected power cables or inactive PDU outlets.
• Stale/full IPMI System Event Log (SEL).
• Possible false alarm

Resolution

1. Verify iLO Status: Log in to the HPE iLO interface to check for physical hardware faults or power management alerts.
2. Clear the SEL: In the vSphere Client, go to Monitor > Hardware Health > System Event Log and click Reset Event Log to clear any stale assertions.
3. Refresh Sensors: Use the Reset Sensors option under Hardware Health to force a re-poll of the IPMI data.
4. If the alert is re-appears,
   1. Power Drain the Server.
   2. Engage Hardware Vendor: Contact HPE Support for further troubleshooting and determine if a component replacement (PSU) is required.

Refer Diagnostics for VMware Cloud Foundation: ESX Health: Hardware Sensor Health for additional details.

Additional Information

Troubleshooting "Status of other host hardware objects" Alarm on VMware ESXi Hosts